CHICAGO – Dressing at one locker was the 28-year-old, seven-year NFL veteran wide receiver who is a master of getting just enough contact with defensive backs to make receptions without drawing flags.

In the adjacent locker was the 22-year-old rookie who apparently needs more schooling from his neighbor.

Bears receiver Alshon Jeffery was playing a critical role as the Bears tried to come back against Green Bay on Sunday at Soldier Field. On one play, Packers cornerback Sam Shields was penalized 5 yards for illegal contact. On the next, safety Morgan Burnett was called for a 53-yard pass interference penalty.

And from there it went downhill quickly for the second-round pick from South Carolina, who was flagged three times for offensive pass interference in the final 15:22 of the Bears’ 21-13 loss.

“It was a physical battle out there,” said Jeffery, who was caught for all three penalties with Shields defending him. “I just have to go back and work hard and study film. I’m not going to put it all on the refs.”

Jeffery (6-foot-3, 216 pounds) has a similar build to Marshall’s (6-4, 230), but Marshall has shown a knack for knowing precisely how to use contact to his advantage. On the first penalty, Jeffery was called for pushing Shields in the end zone on a fourth-and-goal from the 1. Jeffery caught the pass, but the touchdown, which would have cut Green Bay’s lead to 21-14, was nullified.

Jeffery’s other penalties wiped out gains of 7 and 36 yards.

“I play the game physical, the way it’s supposed to be played,” Jeffery said. “[Marshall] talked to me about playing physical. He’s going to talk to me more about it.”

Bears coach Lovie Smith said his team has not received many offensive pass interference calls.

“All of them [today] were really big plays,” Smith said. “Normally, you get a call that goes your way. But we had a lot of opportunities. That’s how the officials saw it.”

Jeffery’s last penalty came on a play that would have put the Bears, trailing 21-13, on the Packers’ 20 with 2:51 remaining in the game. Two plays after that, on fourth-and-9, Shields and Jeffery were at it again, and Shields appeared to grab Jeffery’s jersey on an incomplete pass.

No flag was thrown, and Jeffery shrugged his shoulders at the official at the noncall.

“I don’t think any of us want to get into a penalty discussion of what was right, what should have been called, what shouldn’t have been called,” Bears quarterback Jay Cutler said. “I don’t think anybody wants to get fined, first of all. But secondly, that’s not what lost us the game.”

Shields (5-11, 184) felt Sunday’s game was more physical than usual.

“They probably game-planned and said we need to go in more physical,” Shields said. “I’m a little guy, [Jeffery] is a big guy. I’m just trying to stand my ground and keep covering him.”